<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta http-equiv="X-UA-Compatible" content="ie=edge" />
    <title>Document</title>
    <style>
        * {
            margin: 0;
            padding: 0;
            font: 30px / 90px "微软雅黑";
        }
        
        ul {
            list-style: none;
        }
        
        .wrap {
            width: 1000px;
            height: 1000px;
            position: absolute;
            left: 50%;
            top: 50%;
            margin-top: -500px;
            margin-left: -500px;
            background: url(img/bg.jpg) no-repeat;
        }
        
        .menu {
            width: 330px;
            border-radius: 10px;
            overflow: hidden;
            margin-top: 285px;
            margin-left: 335px;
            background: #f87a75;
            box-shadow: 0 20px 50px rgba(248, 122, 117, 0.5);
        }
        
        .title {
            height: 90px;
            padding-left: 112px;
            box-sizing: border-box;
            color: #fff;
            position: relative;
        }
        
        .title::after {
            content: "";
            position: absolute;
            right: 36px;
            top: 41px;
            background: url(img/ar.png) no-repeat;
            width: 28px;
            height: 16px;
        }
        
        .list {
            width: 316px;
            padding-left: 7px;
            padding-bottom: 5px;
            /* display: none; */
        }
        
        .list li {
            height: 90px;
            margin-bottom: 2px;
            background: #fee4e3;
            border-radius: 20px;
            padding-left: 112px;
            box-sizing: border-box;
            background-position: 23px 24px;
            background-repeat: no-repeat;
        }
        
        .list li:hover {
            background-color: #fff;
            box-shadow: 0 0 50px rgba(248, 122, 117, 0.93);
            position: relative;
        }
        
        .list li:nth-of-type(1) {
            background-image: url(img/icon1.png);
        }
        
        .list li:nth-of-type(2) {
            background-image: url(img/icon2.png);
        }
        
        .list li:nth-of-type(3) {
            background-image: url(img/icon3.png);
        }
        
        .list li:nth-of-type(4) {
            background-image: url(img/icon4.png);
        }
        
        .list li:nth-of-type(5) {
            background-image: url(img/icon5.png);
        }
    </style>
</head>

<body>
    <div class="wrap">
        <div class="menu">
            <div class="title">菜单</div>
            <ul class="list">
                <li>微博</li>
                <li>图片</li>
                <li>博客</li>
                <li>视频</li>
                <li>更多>></li>
            </ul>
        </div>
    </div>
    <script>
        // 获取菜单按钮
        var otit = document.getElementsByClassName("title")[0];
        // 获取列表
        var oli = document.getElementsByClassName("list")[0];
        // 先声明一个true
        var flag = true;
        otit.onclick = function() {
            console.log(flag);
            if (flag) {
                oli.style.display = "block";
            } else {
                oli.style.display = "none";
            }
            flag = !flag;
        };
        // 点击li，获取具体的内容
        var lis = document.getElementsByTagName("li");
        for (let i = 0; i < lis.length; i++) {
            // 此处点击获取具体值有3种方法;

            // 方法一：通过let 声明for循环；
            // for(let i=0;i<lis.length;i++){
            //     lis[i].onclick = function(){
            //         console.log(i);
            //     }
            // }

            // 方法二：通过绑定元素对象
            // for(var i=0;i<lis.length;i++){
            //     lis[i].index = i;
            //     lis[i].onclick = function(){
            //         // console.log(i);
            //         // 获取到点击的对象，this 在事件里会指向事件源；
            //         console.log(this.index);
            //     }
            // }
            /*
                    var i=0;
                    var i=1
                    var i=2
                    var i=3;
                        var li1 = {
                            index:0
                        }

                         var li2 = {
                            index:1
                        }

                          var li3 = {
                            index:2
                        }
                     */

            // 方法三：通过函数作用域 来保持i值；
            /* for (var i = 0; i < lis.length; i++) {
                (function (a) {
                    lis[a].onclick = function () {
                        console.log(a);
                        // 获取到点击的对象，this 在事件里会指向事件源；
                    }
                })(i)
            } */

            lis[i].onclick = function() {
                var text = lis[i].innerHTML;
                console.log(text);
                otit.innerHTML = text;
                oli.style.display = "none";
                flag = true;
            };
        }
    </script>
</body>

</html>